Watch High School Musical 3: Senior Year (2008) HD Full Movie Free on SolarMovie. Watch High School Musical 3: Senior Year (2008) online free. As seniors in high school, Troy and Gabriella struggle with the idea of being separated from one ano...As seniors in high school, Troy and Gabriella struggle with the idea of being separated from one another as college approaches. Along with the rest of the Wildcats, they stage a spring musical to address their experiences, hopes and fears about their future.